He previously played for Feyenoord from 2003–2006 and Chelsea from 2006–2012. While at Chelsea he won numerous honours, including the Premier League, the UEFA Champions League, four FA Cups and the League Cup. He moved to Lille on a free transfer in July 2012 upon the expiry of his contract at Chelsea, where he spent two seasons before moving to Hertha for an undisclosed fee.

He then returned to Feyenoord and played in the Duke top flight for two seasons from 2004 to 2006. During his time at Feyenoord, Salomon scored 35 goals in 67 league appearances for the Rotterdam club, and also won an individual award when he won the Johan Cruijff Award in 2005 for being the most promising young talent of that season. Kalou, together with Dirk Kuyt, were affectionately known as 'K2' by Feyenoord fans and the Dutch Media. 'K2' because they dominated the Feyenoord offensive line-up and it is a play on the words K3, a Belgian pop band.[3]

Kalou moved to Chelsea on 30 May 2006, for an undisclosed fee, believed to be approximately £9 million.[4] Under contract with Chelsea until 2009, Kalou was handed the number 21 jersey.

His Chelsea manager José Mourinho praised the young Ivorian as being hardworking, versatile, eager to improve, and unafraid of the physical side of the game. Kalou admitted that he brought a camera with him to his first training session at Chelsea's training centre at Cobham because he could not believe that he was going to be rubbing shoulders with famous footballers like Michael Ballack, John Terry, and Didier Drogba.[5] Describing the experience, Kalou said:

"This was the dream moment of my life and I did not want to wake up and find that it was not real."

At Chelsea, Kalou played with compatriot, Côte d'Ivoire captain Didier Drogba. Kalou scored his first goals for Chelsea in a reserve game against Portsmouth bagging a hat trick and the match ball in a 5–0 thrashing. Kalou scored his first senior goal for Chelsea in a two-goal win over Blackburn Rovers in the third round of the League Cup.

In December 2006 in Chelsea's 3–2 victory over Wigan Athletic at the JJB Stadium Kalou scored his first Premier League goal. He scored his second Premier League goal against Blackburn in Chelsea's 3–0 win. He also scored a 93rd-minute goal against Watford, putting Chelsea 1–0 up. He also scored a volleyed goal from 12 yards against Tottenham Hotspur in the FA Cup Quarter-Final, which ended 3–3. Chelsea won the replay 1–2, before progressing to the final with a similar scoreline against Blackburn Rovers. Kalou also came on as a substitute in the FA Cup Final win over Manchester United for his second trophy in England, having earlier come on as a substitute for Chelsea in the league Cup Final victory over Arsenal.

Kalou continued his good form into the season that followed, scoring his first goal of the campaign against Manchester City in Chelsea's 6–0 at Stamford Bridge and the opening goal against Derby County in a 2–0 win. Salomon Kalou amassed the record number of offsides in a season with 107 in 30 games; betraying his lack of ability in reading the game.

The 2007–08 League Cup quarter final saw Kalou take up the right wing position of two wing players (the other being Scott Sinclair) of a 4–3–2–1 formation. Kalou made lots of chances for himself and his team-mates; including a very precise left-footed cross, resulting in a Shevchenko headed goal. He thereafter scored goals against Newcastle United and Fulham contributing to Chelsea's success. He scored goals against West Ham United, Olympiacos and Derby County. His last minute cross into the penalty area led to John Arne Riise scoring the own goal in the UEFA Champions League semi-final first leg at Anfield, which gave Chelsea a vital away goal. Kalou also scored with Chelsea's sixth penalty in the Champions League Final in Moscow, where Chelsea lost.

Kalou did not feature much under Avram Grant's successor, Luiz Felipe Scolari except during pre-season, because of his participation in the 2008 Beijing Olympics as part of Côte d'Ivoire's U-23 team. However, he came off the bench against Manchester United on 21 September and scored a header after 80 minutes from a John Obi Mikel free kick.[6] The goal ensured that Chelsea secured a point and kept their unbeaten home record. Kalou then scored two goals and assisted a Frank Lampard header on 18 October in Chelsea's 5–0 win at Middlesbrough.[7]

On the 14th of January 2009, Kalou scored a tap in against Southend United in the third round of the FA Cup as Chelsea ran out 4–1 winners in the replay.[8] Again he scored two goals against Middlesbrough, this time at Stamford Bridge on 28 January, in Chelsea's 2–0 win and was a favourite under interim manager Guus Hiddink.[9] These strikes proved to be his first goal in 15 Premier League games.[10] On 25 April 2009, he scored the winner against London rivals West Ham United.[11] Kalou was an unused substitute in Chelsea's 2–1 defeat of Everton as the Blues won the FA Cup on 30 May.[12]

Kalou and Chelsea began the season in winning form, beating Manchester United to lift the Community Shield with Kalou scoring the winning penalty. Kalou scored his first goal of the 2009–10 season against Queens Park Rangers at Stamford Bridge in the 3rd round of the League Cup, earning his team a deserved 1–0 victory.[13] On 12 October 2009, Kalou signed a new 3-year contract extension with Chelsea, keeping him at Stamford Bridge until the summer of 2012.[14] He celebrated his new contract with an excellent brace against Atlético Madrid in the UEFA Champions League, helping Chelsea maintain their 100% record in the competition. Kalou continued his good form scoring a header in the 4–0 win against Bolton in the League Cup. He also netted in the Blues' League Cup loss to Blackburn Rovers, but it was his last goal for two months until he broke the duck against Cardiff City in the FA Cup on 13 February 2010.[15]

During those two months without scoring, Kalou struggled for game-time and the goal against the Bluebirds was one he really needed. On 24 February he scored a good goal against Inter Milan in the Champions League second round first leg. His shot from outside the box was tame but an error from Inter goalkeeper Júlio César allowed the ball to find the back of the net. Chelsea however lost the leg 2–1, but Kalou's goal was important as it was a much needed away goal for Chelsea.[16] He finally netted a goal in the Premier League on 27 March in Chelsea's astounding 7–1 win over Aston Villa at Stamford Bridge.[17] In Chelsea's 7–0 win over Stoke City on 25 April Kalou netted a hat-trick, though his second goal of the day had been the source of controversy, as it was very close to being a two-footed tackle.[18] Kalou scored Chelsea's third of eight goals on the last day of the season against Wigan Athletic, after some clever teamwork with Frank Lampard.[19] Following the game, Kalou won his first ever Premier League winners' medal as Chelsea were crowned champions.[20]

Kalou started the season well with scoring the only goal in the 3–1 defeat at Wembley Stadium against Manchester United. He appeared as a substitute in the 6–0 drubbing of Wigan Athletic at the DW Stadium, to score 2 goals both assisted by fellow Ivorian Didier Drogba.[21] Kalou played 84 minutes of Chelsea's 3–1 win at West Ham United, scoring Chelsea's second goal of the game. He continued his scoring run the following week scoring only 2 minutes into the game to grab Chelsea's first goal in a win against Blackpool. He also scored a goal against Wolverhampton Wanderers. In the FA Cup fourth round game against Everton, Kalou scored a late leveler to keep chelsea in the cup with the game ending 1–1 at Goodison Park, and therefore resulting in a replay at Stamford Bridge. On 1 February, the day after Fernando Torres was signed from Liverpool, Kalou continued his fine scoring run, netting the second goal against Sunderland in a 4–2 victory for Chelsea at the Stadium of Light.[22]

Through 31 appearances Kalou had scored 14 goals in all competitions. Despite his form he found it hard to gain a regular first team place since the addition of Fernando Torres in January.[23] But he was included in the starting lineup for their next game against West Brom, scoring a goal in Chelsea's 3–1 win on 16 April.[24] Kalou started the next game as well, and scored again as Chelsea defeated Birmingham 3–1.[25] For Chelsea's crucial game against Tottenham, Kalou was not included in the starting lineup as Carlo Ancelotti preferred a striking partnership of Drogba and Torres. But Kalou replaced Torres in the 63rd minute, and scored a goal in the 89th minute, propelling Chelsea to a 2–1 win and within three points of leaders Manchester United.[26] This brought him up to 10 Premier League goals, the first time he has hit double digit league goals for Chelsea.[27]

Kalou started this season in Chelsea in the second game of the season against West Bromwich Albion, substituted after only 34 minutes.[28] He was an unused sub against Sunderland and Bayer Leverkusen,[29][30] but he started in Chelsea's first League Cup match of the season against Fulham. Chelsea won 4–3 on penalties as he scored the second last penalty.[31] On Wednesday 28 September 2011, Kalou came on for Frank Lampard in the 83rd minute. He then was booked for handball in the 85th minute which led to Roberto Soldado scoring a penalty, the score ended up at 1–1.[32] Kalou's first goal of the new season came in a 5–0 rout of Belgian side Genk on 19 October 2011. Salomon scored in a 2–1 win at Goodison Park against Everton in the League Cup. He scored his first goal in the League in a 3–0 away win against Newcastle United.[33]

Following the appointment of Roberto di Matteo as interim boss, Kalou began a new lease on life as he fought his way back into the first team squad. Under Andre Villas-Boas, he was frozen out, only making four starts in over seven months.[34] Kalou scored his first goal in the season's edition of the FA Cup when Chelsea defeated Leicester City 5–2 at Stamford Bridge.[35] This goal put him alongside Sergio Agüero as the only players to score in the Premier League, League Cup, FA Cup and Champions League in the season. Kalou then netted a vital away goal in the first leg of their Champions League quarterfinal clash with Benfica after some great work from strike partner Fernando Torres, Chelsea won the game 1–0.[36] Kalou's goal against Benfica was his 58th for the club. On 29 March 2012, he claimed he was frozen out by former Chelsea manager Andre Villas Boas.[37] He came on in the 74th minute to replace Juan Mata in the 1–0 victory against Barcelona in the first leg of the Champions League semi-final, the only goal coming from his Ivorian team mate Didier Drogba.[38] On 21 April, Kalou made his 250th appearance for Chelsea in a 0–0 draw away to rivals Arsenal. He started both the 2012 FA Cup Final and 2012 UEFA Champions League Final, in both of which Chelsea recorded victories.[39][40]

On 1 July 2012, Chelsea officially announced that Kalou's contract had come to an end along with José Bosingwa, after spending six years at the London side. The club stated: "Chelsea Football Club today bids farewell to Salomon Kalou, who has come to the end of his contract"; Kalou made 254 appearances for the club, including 147 starts, and scored 60 goals. After his release, Kalou was linked with numerous big clubs across Europe including the likes of Schalke 04,[41]Liverpool,[42]Galatasaray,[43]Newcastle United[44] and Arsenal.[45]

On 7 July 2012, it was confirmed that Kalou would sign for Lille on a free transfer after being released by Chelsea at the end of his contract.[46] He was given the number 8 jersey, manager Rudi Garcia was pleased to see Kalou join Lille but admits that it wasn't easy to convince him to join the French side.[47] Kalou scored his first competitive goal for Lille in his second appearance; a header to equalize the score against AS Nancy.

His first Champions League goal for the club came in their 6–1 humbling defeat to Bayern Munich on 7 November.[48] Kalou netted in Lille's next fixture at home to Brest, giving his side a much needed 1–0 win.[49]

Kalou received much media attention regarding his possible naturalization as a Dutch citizen which, if granted, would allow him to play for the Netherlands national football team. Having never played for the Côte d'Ivoire team, he would be eligible for the Dutch team if he was naturalized. His brother Bonaventure had advised him to pursue foreign citizenship after frequently experiencing problems with the Côte d'Ivoire football authorities.

The Dutch national team head coach, Marco van Basten, regarded Kalou as a great talent, so an official application was quickly made. However the Minister of Immigration Rita Verdonk was opposed to considering Kalou for an accelerated naturalization process.

Van Basten, keen to show Kalou's worth to the Dutch team, obtained support from influential football figures, including Dutch legend Johan Cruyff. Despite general agreement among football pundits that Kalou would be valuable for the Dutch team, Verdonk rejected a request for reconsideration. Later Cruyff commented that the Dutch national team might have been more successful had Kalou obtained Dutch citizenship.

Kalou appealed the decision and took the matter to a court of law, gaining a victory on 9 December 2005 when the judge ordered Verdonk to reconsider whether or not Kalou could be considered for accelerated naturalization. Verdonk had decided to appeal, placing the matter before the Council of State. Kalou has since then publicly stated he has given up hope of ever attaining the Dutch nationality.[51]

At the 2006 World Cup, the Netherlands and Ivory Coast were drawn in the same group in the first round. Kalou's failure to acquire Dutch citizenship was a factor in his decision to leave Feyenoord for Chelsea.[54]

Kalou playing for Ivory Coast in 2007

He had been named in the Ivory Coast national squad on a number of occasions, however he rejected[55] all call ups until 6 February 2007 when he finally made his Ivory Coast debut in the friendly against Guinea, where the Elephants ran out 1–0 winners. He also featured in the Elephant's African Cup of Nations and scored a terrific goal to stun co-favourites Nigeria in the opening game.[56]

After failing to obtain his Dutch passport, Kalou decided to play for Ivory Coast. His first international goal was scored on 21 March 2007 in a friendly against Mauritius.[57] He played at the 2008 Africa Cup of Nations with the team, scoring 3 goals in the process, and reached fourth place after losing to Ghana in the third place play-off.

Kalou has two brothers and eight sisters from the same mother. His brother, Bonaventure Kalou, also played professional football. Salomon joined Feyenoord during the time his brother Bonaventure was playing for the club from Rotterdam.[59]

In 2010 he set up The Kalou Foundation dedicated to providing facilities for social welfare and recreation of those who have need of such facilities by reason of youth, age, infirmity or disability, financial hardship or social circumstances and also for the relief of sickness worldwide.[60][61][62][63]